Variable capacity rotary pump



Sept. 3, 1957 Filed June 9-, 1953 G. E. RYDBERG VARIABLE CAPACITY ROTARY PUMP 6 Sheets-Sheet 1 INVENTOR. BY fl George E m/'/ Rydberg Sept. 3, 1957 George Emil Rydberg 1N VEN TOR Sept. 3, 1957 G. E. RYDBERG 2,804,827

VARIABLE CAPACITY'ROTARY PUMP Filed June 9, 1953 6 Sheets-Sheet 3 George Emil erg IN NTOR.

Sept. 3, 1957 e; E. RYDBERG VARIABLE CAPACITY ROTARY PUMP 6 Sheets-Sheet 4 Filed June 9, 1953 H0 6M m M R m b E W @W 0 Y e B G Sept. 3, 1957 G. E. RYDBERG VARIABLE CAPACITY ROTARY PUMP Filed June 9, 1953 6 Sheets-Sheet 5 Fig. /8

INVENTOR.

g m M R m NW P 1957 G. E. RYDBERG 2,804,827

vARiABLE CAPACITY ROTARY PUMP Filed June 9, 1953 a Shets-Sheete Fig. 2/-

George Emil Rydberg IN VEN TOR.

Unite This invention pertains to novel and useful improvements in rotary pumps and motors for use with fluid pressure mediums, and more specifically pertains to an improved rotary pump having a controllable variable capacity which is varied in accordance with its speed of rotation.

The principal object of this invention is to provide a rotary pump or motor unit for operating with fluid pressure mediums and wherein the construction thereof shall be simplified by reducing the number of parts, by eliminating the rotational unbalance caused by reciprocating masses, as in the customary cylinder, piston and crank shaft constructions; and wherein a positive displacement is obtained in the use of a fluid pressure medium.

A further important object of the invention is to provide a rotary pump or motor unit in accordance with the foregoing object in which the parts of the device are reduced to a minimum and are compactly assembled.

A further important object of the invention is to provlde a rotary unit in conformity with the above-mentioned objects in which the fluid pressures are effectively balanced in the construction of the apparatus in order to reduce the wear and strain upon the various parts of the mechanism.

Yet another important object of the invention is to provide a rotary unit in accordance with the preceding objects together with means for obtaining any desired variation of the-capacity of the unit while readily controlling such variation.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a diagrammatic plan view illustrating the manner in which the rotary pump and motor units in accordance with this invention may be employed as part of a fluid drive of an automotive vehicle, certain parts being indicated in dotted lines therein;

Figure 2 is a vertical central longitudinal sectional view taken substantially upon the plane indicated by the section line 2-2 of Figure l and showing the internal construction of a variable capacity pump unit in accordance with this invention, the position of certain concealed parts being indicated in dotted lines therein;

Figure 3 is a vertical transverse sectional viewtaken substantially upon the plane indicated by the sectionline 3-45 of Figure 2 and showing the operatingchamber of the unit; 1 Q

V Figure 4 is a vertical transverse sectional view taken substantially upon the plane indicated by the section line 4-4 of Figure 2 and showing a part of a connecting member comprising an element of the invention; 7

Figure S'is a vertical transverse sectional view taken substantially upon the plane indicated by the broken sec- States Patent tion line 5-5' of Figure 2, this view beingtaken atsub- 23%,827 Patented Sept. 3, 1957 stantially the same place but looking in the reverse direction from that of Figure 4;

Figure 6 is a vertical transverse sectional view taken substantially upon the plane indicated by the section line 6-6 of Figure 2, parts being broken away;

Figure 7 is a vertical transverse sectional View taken substantially upon the plane indicated by the section line 7-7 of Figure 2, this view'being taken upon the same plane as Figure 3 but looking in the reverse direction;

Figure 8 is a perspective view of a rotor forming a part of the invention and of a ring associated therewith;

Figures 9-11 are diagrammatic views similar to Figure 7 and showing in connection with that figure successive positions assumed by the rotor and ring during the opera-' tion of the'unitg' I I Figure 12 is a vertical transverse sectional view taken substantially upon the plane indicated by the section line 12--1Z 0f Figure 2 and showing certain details of the fluid pressure exhaust chamber of the unit;

Figure 13 is an exploded perspective view of two rotor elements forming a partof the working chamber of the invention;

Figure 14 is an exploded perspective view of a ring and the sleeve carrier therefor;

Figure 15 is a perspective view of a connecting member for securing the sleeve carrier to a rotor of the invention;-

Figures 16 and 17 are exploded perspective views of two universal joint connecting assemblies for connecting the connecting sleeve to the ring carrier and to a rotor of the unit;

Figure 18 is a vertical longitudinal sectional view, similar to Figure 2, but showing a simplified and modified construction of the unit when the same is adapted to function as a constant capacity unit; I

Figure 19 is a vertical transverse sectional view taken substantially upon the plane indicated by the section line 19-19 of Figure 18;

Figure 20 is a vertical transverse sectional view taken substantially upon the plane indicated by the section line 2020 of Figure 18;

Figure 21 is a perspective view of the modified form of ring carrier and ring forming an integral assembly in the modified construction of Figure 18;

Figure 22 is a perspective view of arotor unit forming .a part of Figure 18; and

Figure 23 is a perspective view of a connecting sleeve for operatively connecting the unitary ring and ring holder with the rotor of Figure 18.

This invention relates to a rotary unit which maybe optionally employed as either a fluid pressure pump or a fluid pressure motor, depending upon the manner in which it is employed. 'This unit may be either a variable capacity pump or a variable capacitor motor, and it is this variable capacity unit which has beenillustrated in Figures l'17. In some instances the unit may be constructed and employed as a constant capacity unit, and when intended for such functioning the units construction may be simplified in accordance with the modified embodiment illustrated in Figures 1823. V c r a In Figure l is shown in diagrammatic form a system wherein a plurality of the units may be employed as a part of a hydraulic transmission for automotive vehicles. The assembly of Figure 1 is to be understood as being anjillustration only of the principles of theinve'ntion and a possible use for the invention, and not as; a limitation thereof. In Figure 1 a variable capacity unit indicated generally by thenu meral 10 is shown in operative relationship to a plurality units each indicated generally by the numerallz, and the unit 10 is preferably of the variable capacity construction illustrated in Figures 1-17, while eachgof the driven motor units 12-, in any desired manner,

whereby-thelpower from the engine ,14 will be delivered to the pumpil l and from theme by means of a fiuid mediumnnderlpressure to theindividual driven units 12 V andeajch of thezwheelsof-the vehicle. 2

sinzce the presentrinvention is not concerned with the actual use. of theunits 10. or 12, nor the connecting and control system of conduits therebetween, a, further description and explanation of the same is deemed to be ,-As 1shown in ;Eigure 2,v the variable capacity pump or driving unit ltl' zcompri'sesapair' t casing sections 22 and 24 which areidetachablyiseeured together as by fastening bolts26 At; the free end of the section 22 there is; removably secured a further housing 28 as'by means of fasteners 30. V i i a v Disposed within the casing are; the movable elements of theivariablecapacity pump. These elements include a. pair ofrotors, the numeral; 32 indicating generally the drivingjrotor 'or piston of-the unit while the numeral 34 designatessavolume varying rotor, V 7

; ;Referring, particularly to Figure 13, the driving rotor includes a cylindrical or drum-like member 36 having an axially extending tubular sleeve 38 extending from what may betermed itsrear face' An axial bore -40 disposed through the drum 36 constitutes a continuation of the internal bore of the stem-38. V

T;'he -,volume vjarying rotor 34 likewise includes 2. cylindrical drum 4 2- which' has'an axiallyextending stem or rod 44 extending from its rear face and adapted to be slidably,received' within the bore 40 and stem 38- of the rOtOI2132-t v, v

Extending forwardly from the front face; of the, rotor drum 42 isa;;cylindrical-fprojection 46 having anaxial relce s's, IISOCket148 in the forwardendjof the-same. As

will be more readily apparent from. Figure 2, the'rearfaceaof the. rotor; drum 42is provided witha cylindrical recess or chamber 50 which slidably receives thereinthe rotoradrum; 36. The ,rotordrums -36 and 42am, respectively provided with boresor passages 52: and 54 ,respectively whereby a fluid medium may freely? passfrom one sidetO the, othetside of these rotor-drums.

Ihe gcasingsection-lj l is-provided' with a cylindrical chamber 56 which extends inwardly from1theopen face of-thesection-to the end wall SSIhere'of and in which is s id bly ie v d h ro or d m; .2 h e d. W is provided with-.an-integral centrally disposed cyliridert) having a chamber 62 having its inner. end extending into the chamber 56 lying within the cylindrical section 24, and which has its outer end extending outwardly of the end wall 58, being provided witha rifintegral'closure' 64. The sleeve 60' receives for sliding and rotating movement thecylindrical projection 46 of the rotor 34'.

An anti frictionbearing assembly 66 is seated in the bottom ofthe recess or socket 48 and-constitutes a-seat for one end ofa-compression spring 68, the other end ofthi's-spring s'eatingnpona boss '70 extending inwardly As will be appar om F g e e e of he rotor 32 is slidably received upon the shaft or stem 44 of the rotor 34, while the rotor drum 36 is slidably received within the chamber 50 within the drum 42. The casing section 22 has an end Wall 76 which is axially bored to slidably and rotatably receive the stem 38 therein, the ends of the stems,38 and 44 being disposed within the housing 28. A conventional sealing assembly is provided fortheprojecting 'ends of the stems 38 and 44, such assembly being designated generally by the numeral '78. Fixedly secured to the projecting end of the stem 38 asrby' fasteners. 80' is a plate 82 having pairs of lugs or cars, 84 thereon which are provided with fulcrum pins 86 whereby a pair of lever arms 88 are pivoted. These lever arms at one end are provided with fly wheel-governor weights 90 and at their other ends engage the extremity of the shaft 44 whereby the governor weights 90 willurge the levers 88 in a direction'to move the stem 44 to the right against resistance of the spring68'as the speed of rotation ofthe two. stems increases. This movement of the stem '44 relative to the sternglitiunder the influence'ofincreases in speed is relied upon as a means for increasing the capacity or ya vme Qt do e err of t e variable pacity p p-V l-t is' contemplated that the stem 38 will be connected in any. desired manner to the engine 14, in the assembly shown in Fignre l, or to any other power source in order to imparb rotary movement. to the variable capacity p mr a t- Iherotor lizr iskeyed to the rotor 34 whereby relative sliding or axial movement is permitted, but the two rotors revolve-- -as a unit. For this purpose, as will be clearly apparent frorn Figure 13, the rotor drum 42 is Figure-7.

frornthe end wall64.-- The spring thus serves to urge the vo-lume varying rotor 34 towards the left as .viewed in Figure 2, and thus tends to. slidably urgethe rotor drum 42 outwardly from the chamber 62'.- .,Intermediate theopposite ends 0t thecylindrica-l wall 5 6.there isprovided a circumferentially extending groove '12 which is covered at all times by the periphery of-the rotor drum 42.

provided with a radially extending slot ornotch 92 extending radially inwardly/ from the cylindrical periphery of the drum 42,;and extending axially across the entire width of the same. The'rotorldrum 36 is provided with a ra-dially extendi-ng key or block 94- which extends entirely across thewidth of the rotor drum 36, and over hangs the forward'end of thesame, This key- 94 is adapted to slidably move in the slot 92 and fills the cross-sectional area of the same, but the overhanging or forwardportion 96 of the key'extends into the slot 92 for yarying distances in accordance with the relative axial positions" of the rotor assemblies 32 and 34.

Disposed within the casing section' 22 is a'cylindrical chamber fil8 'lhe chamber 9;8 has a central axis ltltl which is displaced; vertically from the, axis 102 of the stems 38 1and 44 and the peripheral surfaces of the rotor bloccs 36 and 42 as well as the cylindrical surface 56 of thefehamber jlI-hiseccentricity; for displacement of the; axes 102 is clearly shown in Figure 2, as well as in The 'ii i r i aid o .v'h mb 2 basa t annular shoulder "1G4 .wliichis seated an anti-friction bearingassembly indicated generally by the numeral 106 whose inner bearing; race 108 see also Figure 5, is secured as-by fasteners I IG to the rear endof a cylindrical annulus or rotor 11 2 which rc onstitiitesQa' ring holder asset forth'hereina fter and which thus revolves about the axis Referring now to Figure 14 it will be seen that the cylindrical annulus 112' which constitutes the ring ca'rrieris provided upoiiits for ward face with a circumferiential" groove or recess 114' which extends throughout alrriost a complete. circle, l iavin g it s ends spaced.

The forward face of the annulus 112, which is the face having the groove 114, is adapted to abut against the; adjacent" pane, face ot the extremity of the casing section124,asclearly.'shownfin'FiguiL2; I I e As soiiardeseribed, it willjiiow be ;senj that an annular chamber 116 constituting the working chamber ofQthe unit 10; is forrnedfhaving'a cylindricalkconcave formed by. the wall .56'; .a' convex cylindrical wall formed by theperipherybf the rotor druni 36; and a pair of annular end walls formed by the adjacent parallel plane faces of the ring' holder 112 and the annular rim of the rotor 42 which is axially slidable between the con vex and concave cylindrical surfaces just mentioned.

Extending from the rear face of the ring holder 112 are a plurality of parallel Wells or recesses 118 each of which intersects the bottom of the circular groove 114. These recesses, have their open rear ends, shown also in Figure 5, closed by the plate 108 constituting the inner race of the bearing assembly 106 as previously mentioned. A compression spring 120 is seated in each of the recesses 118 and has one extremity bearing against the closure plate 108 and has its other extremity engaging a spring seat in the form of a disk or plug 122, which is slidable in the recess 118. A ring 124, is provided, which is slidable axially of the annulus or ring keeper 112 within the ring groove 114, this ring having a plurality of parallel axially extending and rearwardly e tending projections or fingers 126, each of which is adapted to extend into and be slidable in one of the wells 118. The spring seats 122 engage the extremitites of the fingers 126 and thus the force of the springs 118 yieldingly urges the ring towards the right asviewed in Figures 14 and 2 to thus yieldingly urge the ring 124 from the recess 114 and into and across the chamber 116 and into contact with the annular face upon the rim of the rotor drum 42.

Since the ring 124 and the ring groove 114 are concentric with respect to the axis of the ring holder 112, being concentric with respect to the axis 100, they are eccentric with respect to the axis 102. Consequently, upon rotation of the ring holder and ring, and the two rotor drums about their parallel axes, the ring will have an eccentric motion in the chamber 116.

The eccentric travel of the ring within the chamber 116 between the concave and convex cylindrical surfaces will be more readily perceived from a comparison of Figures 7, 9-11 which show sequential positions during a complete revolution of these members.

Although the stems 38, 44 and the ring holder 112 rotate about different axes, a connecting means is provided between these members whereby the stems will constitute a driving means for the ring holder to cause rotation of the latter. This connecting means as shown especially in Figures 2, 15-17 consists of a sleeve 128 which has a pair of axially extending parallel lugs or cars 130 and 132 at its opposite extremities. The ears 130 have inwardly extending diametrically opposed connecting pins 134 while a similar pair of outwardly diametrically disposed pins 136 is provided upon the other pair of ears 132. The pins 134 and 136 are respectively'connected to the sleeve 38 and to the ring holder 112. j

The pins 134 and the stem 38 are connected by the coupling means shown in Figure 16, while the pins 136 and the ring holder 112 are secured by the coupling means of Figure 17. Referring to Figures 13 and 14, it will be seen that the stem 38 is provided with a pair. of diametrically disposed outwardly extending coupling pins 138, while the annulus 112 is provided adjacent its right end with a pair of diametrically disposed inwardly extending pins 140. Y

The coupling means of Figure 16 includes a pair of rings 142 and 144 having complementary faces provided with two pairs of diametrically disposed semi-cylindrical bearing recesses 146 and 148. Suitable fasteners 150 serve to removably couple and secure the rings 142 and 144 together. The pair of bearing recesses 146 are adapted to receive and journal the pair of pins 134 of the connecting sleeve 128, while the other pair of bearing recesses 148 are connected to and journaled upon thepair of pins 138 of the stem 38. Thus the stem 38 is rotatably connected to the sleeve 128 whereby the formerwill rotate the latter despite the displacement of their axes of rotation, the axis of the sleeve being inclined with 6 respect to the axis of the stem 38 as willbe apparent from Figure 2..

The other coupling member of Figure-17 is of similar.

construction, comprising a pair ofcoupling rings 152 and 154, each of which is provided with two pairs of diametrically disposed semi-cylindrical bearing recesses 156 and 158. As in the other coupling member, suitable fasteners 160 serve to removably secure the coupling rings together and upon the connecting sleeve 128 and the ring holder 112.

The diametrically disposed pair of bearing recesses 156 of the coupling rings 152 and 154 are adapted to be connected to and journaled upon the pair of pins 140 of the ring holder 112, while the other pair of bearing recesses 158 are adapted to journal and embrace the pins 136 upon the connecting sleeve 128. It will thus be apparent that the connecting sleeve together with the two coupling members constitutes a universal joint coupling which drivingly connects the sleeve 38 to the ring holder 112 whereby rotation of the former will cause rotation of the latter about parallel axes of rotation, and 102.

Referring now again to Figure 13 and to Figures 6 and 7, it will be seen that the rotor drum 42 is provided on one side of the slot 92 with a passage or bore 162 which is parallel to the axis of the stem 44 and which extends entirely through the rotor drum. This passage establishes communication between the chamber 56 and the chamber 116, at all times, and when the unit functions as a pump constitutes the inlet passage to the pump.

Upon the other side of the notch 92 the rotor drum 42 is provided with an axially extending passage 164 which is L-shaped, having a radially outwardly extending leg 166 opening to the periphery of the rotor drum and registering at all times with the annular groove or channel 72. The L-shaped channel 164, 166, when the unit functions as a pump, constitutes a fluid outlet means from the chamber 116, with which the horizontal or axial leg of the passage at all times communicates.

The chamber 56 thus constitutes a fluid inlet chamber for the pump and fluid is supplied to this chamber by means of a pipe or. conduit 1 68 from any suitablesource. The chamber 72 which is the exhaust chamber for the pumping chamber 116, is connected by a passage means 170, see Figure 2, with the chamber 62 formed between the end wall 64 and the outer extremity of the rotor drum 42 within the sleeve or cylinder 60. This chamber in turn is connected with a discharge conduit 172 which delivers the fluid under the pressure generated with the pump to any suitable destination, as for example, one of the rotor motor units 12.

It will be seen that the vent passages 52 and 54 serve to equalize the fluid pressure applied to the opposite faces of the rotordrums 36 and 42 to facilitate their axial adjustment under the influence of the governor mechanism previously described; y

Referring now to Figures 3, 7, 9-11, it will be seen that the ring 124 divides the annular chamber 116, into two concentric chambers. Thus, the adjacent ends of the ring are disposed on opposite sides of and are spaced from the key member 94. Further, since the ring is eccentric with respectto the chamber'116, it will be seen from Figure 7 that the ring is tangent to-the rotor drum 36 and to the concave cylindrical Wall' of the chamber 56 upon a vertical diameter through these elements. During operation of the device, this point of tangency remains upon the vertical diameter. There is thus prey vided an outer chamber 174 which lies radially outwardly of the ring 124 and radially inwardly of the cylindrical wall of the chamber 56. V, The ring also providesan inner chamber 176 which lies within the ring and between the ring and the. exterior surface of their'otordrum 36, 7

. The key 94, which functions as a piston orimpeller in 7 the chamber 116, rotates in-la counter-clockwise direction I 5 as shown bythe arrows in Figures 7.,-- 9-; 11;. This rota.

tiin of the'piiiioii 94, ah ro the" ring 1 24- with pointsiofi tangency of the ring with the adjacent suffa'ces of the members 36"ai1h -56'-rerrfaining stationary upon a vertioal diameter, constantly decreases: the volumeof the chambets- 17412156: 176"o1ithe forward or advance side of the piston 94;" and increases the v'ol'uin'e' of the chamber 175 arid- 177 on'the fear or trailing side of the piston 94.

-.-As1 the piston 94' and ring 124 rotate inthe chamber 116 in the direction' of thearrows' and' as shown in sequence in Figures 7, 9-11, the motive fluidis forced from the decreasing; charnBersLI74, 176 and discharged from the passages 164;: 166', into the a'nhular' channel" 72 and; frdnf thence to the chamber 62' by the passage 170 and from: thence to the discharge conduit. 172. g ..1 At thesame time; the'enlargirig chambers .175 and 177 receive or intake aiih'ai'ge of the motive ,fiuid through the inlet conduit 168; chamberSG and the intake passage162';

- When'the' pistonatrei'ther the upper or lower positionsilof' tangeny of the ring 124, the volume of the chambers 174, 176 in advance of the pis'tonis equal to that of thecl'tarnbers 175,'.1'77at1the're ar of the piston It will: alsobe observed that thepressure at which the Mid will beappliedto the outer or righthand end 'of the projection 46 of therotor drum 42, thereby tending to urg'ethe rotor :34' toward theleft; This sliding movement of:,the rotor 34 toward the rotor 32 will cause the rirniof the rotor drum 42 to penetrate further into the chamber 116, this inward movement causing the ring to be drivenintolthe' ringgroove', against the resistance of the. springsl-IS, thereby-contracting or reducing the volumeof the chamber 116 andIthe're'fore the capacity ofthe,purnp: 1 U v 1 .AS'EIhQSPEed or the unitincreases, the governohmenthers 90. and; 88 will tenjdto' separate the drums thereby increasing the volume of theworking chamber of the de- VICE.

r. In the modification described hereinabove, the device is; of the variable capacity type. "Where it is not desired to .vary the capacity, but to obtain a constant volume .-or .capacity, as when the device is to be emp19Yd..as a; fiuidhnotor such as the units 12-, a simplification: of the above described construction is pos- Sible by omitting the'volume varying means and combining-previously distinct elements. For such a construction attentionuis directed to the embodiment of Figures;18:2 3 wherein; the same principle of construction and-operation exceptfor the volume varying feature is dis l ed.

Thus, the unit 12 includes a .pair' of 'casing' sections Ziltland, 202 which are,detachably-connected as by fasnet 1 04..

illustrated .is identical the memherllathe. emberzm is similar to'but' slightly modified from the construction of the memberi24, while the-two sections are coupled together by .the fasteners 204 in the same manner as the previously described sections were; connected by the fasteners 26. However, in

place of the twoseparate rotors 32 and 34, there is provided a single rotor 20 6. As shown more clearly in Figure 22', the rotor 206 consists of a stem 208 having thereon a pair; of diametrically disposed oppositely extending pins 210;,which jcorrespond to the previously a iiylindricalaxial extension 220 which correspofids to' th'' proiection or' extension toof the motor' drum 42a- The casingsectioh 202*:is pr'oviddwith a centrally di's-' posed axially and outwardly eiitending cylinder 222 inwhich is'- joum'aled the extension 220; an anti-frictiion y cares with. a: conduit 232' and therewith constitutes the inlet means for the'unit 12.

As in the'preceding embodiment, the casing section is provided with a cylindrical bore or chamber 234 in which is rotatably received" the member 214; this chainber having an annular groove or channel 236 therein corresponding to the previously described channel 72.

A' conduit 238 is connected to' a passage 240 communieating with the interior of the channel: 236, this conduit andchannel corresponding to the previously described passage 170 and conduit 172. Communication is established between the" channel 236 and the chamber 219 by means of the outlet passage 01' port 242 formed in the member 214 and registering with the channel 236.

The casing section 200 has a cylindrical but eccentri'cally disposed. chamber or bore 244 corresponding to the borev 98 and having an annular bottom wall 246 corresponding to the shoulder or. wall 104; with a bearing assembly248 resting against this bottom wall. The bearing assembly includes a plate 250 comprising one race of the 7 bearing and which plate is rernovably secured as by fasmentioned pins, 138, At one extremity the stem 208'is provided with an' integral cylindrical drum 212 which is surrounded by a cylindrical rirn or flange 214 integrally-corir iected to the drum at the forward edges of both these members by the annular. integral flange or plate Ai radial 'rib or web 218 connects the eit'ei'ior ,surjffa ceofjhe drum 212 with the interior the member 214mm serves as a the r space therebetween. This an- ,cornp sesa ch'airiber' 219 which corresponds tern neer fig 111'- tfiefpr'ecedi'rig' e bodiment.

' Y is strewn in- Figure '1'8;the mehrbers 212 and 216have teners 252to the rear end'of a ring holder 254; As shown in Figure 21, the ring holder. 254 has an. integral axially extending concentric ring 256 at one end, this ring correspondingto. the, ring 124. It will thus be seen that the ring holder of Figure 21 combines as a single element the ring holder 112 and ring 124 previously described, the ring holder having an axial bore 258 therethrough.

The ring. extends into the chamber 219 and operates therein in the same manner, since the ring rotates about an axis" which is eccentric to that of the rotor carrying theschamber.

,,The same connecting means previously described is utilized to establish a driving connection between the rotor stern 208 and the ring; holder. For this purpose, there are provided a pair of diametrically disposed inwardly extending coupling pins260 upon the ring holder 254 within the Bore 2535i thereo f which are connected to a connecting sleeve 22 see Figu re 23, which in turn is connected tothepins 21:0 upon the stem 208.

The connecting sleeve 262 has pairs of oppositely disposed lugs 264 and 265 estndrfi rm'm opposite ends of messin these lugs having, pairs of diametrically dis posed 'outw'ardly and,inwardlyjextending pins 268 and 270;,.respectively.ICouplirig rings indicated generally 272 arid 274', and which may be substan- H i l with the 'cdupling rings of Figures 17 and 1'6, fespec'tiyely, "of'the previously described embodiment are utilized to connect the pins'268 and 27.0' to the pins 2602i 2E0; "r 'r e f Tflie operation'of thisrform of the invention is identical with that'pr'e'viciu sly described except that there is no variation in the oluine of the working chamber 219, the ring 256 extending into this Chamber 219 dividing the samei noesseentiic chambers 276 and 278, as shown in Figure 20 Since the' operatiouof this form of the invention is identical Minibar-previously I'd'escribed except that. the chamber is :sr constant instead'of variable volume a further description" ofthe same appears to be unnecessary.

TfFro'rn thez-'fore'goitig,xsthe construction and operation of: the;de'vic'e;will,be readily understood and further. ex-

planation is believed to be unnecessary. However, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the appended claims.

What is claimed as new is as follows: ing an annular pump chamber therein, said pump chamber 1. A variable capacity pump comprising a stator havhaving concentric cylindrical inner and outer walls together with annular side walls, first, second and third rotors journaled in said stator, said first and second rotors having a common axis of rotation displaced from that of said third rotor, said first rotor having a peripheral surface constituting said innerwall, said second rotor having a surface disposed between said inner and outer walls and constituting one of said annular side walls, said third rotor having a surface constituting the other of said side walls, a ring disposed in said pump chamber, fluid inlet and outlet means for said pump chamber, means for moving said second rotor to vary the volume of said pump chamber, the displacement of said axes being suflicient to bring the concave and convex surfaces of the ring into sealing engagement with the convex surfaces of the second rotor and the concave surface of the stator.

2. A variable capacity pump comprising a stator having an annular pump chamber therein, said pump chamber having concentric cylindrical inner and outer walls together with annular side walls, first, second and third rotors journaled in said stator, said first rotor having a peripheral surface constituting said inner wall, said second rotor having a surface disposed between said inner and outer walls and constituting one of said annular side walls, said third rotor having a surface constituting the other of said side walls, a pump impeller disposed in said pump chamber, fluid inlet and outlet means for said pump chamber, means for moving said second rotor to vary the volume of said pump chamber, a ring carried by said third rotor, said ring having a sealing engagement With the surface of said second rotor.

3. A variable capacity pump comprising a stator having an annular pump chamber therein, said pump chamber having concentric cylindrical inner and outer walls together with annular side walls, first, second and third rotors journaled in said stator, said first rotor having a peripheral surface constituting said inner wall, said second rotor having a surface disposed between said inner wall, said second rotor having a surface disposed between said inner and outer walls and constituting one of said annular side walls, said third rotor having a surface constituting the other of said side walls, a pump impeller disposed in said pump chamber, fluid inlet and outlet means for said pump chamber, means for moving said second rotor to vary the volume of said pump chamber, a ring carried by said third rotor, said ring having a sealing engagement with the surface of said second rotor, said third rotor having a groove in said surface, said ring being movably seated in said groove, means resiliently urging said ring outwardly of said groove and into sealing engagement with the surface of said second rotor.

4. A variable capacity pump comprising a stator having an annular pump chamber therein, said pump chamber having concentric cylindrical inner and outer walls together with annularside walls, first, second and third rotors journaled in said stator, said first rotor having a peripheral surface constituting said inner wall, said second rotor having a surface disposed between said inner and outer walls and constituting one of said annular side walls, said third rotor having a surface constituting the other of said side walls, a pump impeller disposed in said pump chamber, fluid inlet and outlet means for said pump chamber, means for moving said second rotor to vary the volume of said pump chamben'said last mentioned means being operatively connected with the fluid outlet means outer walls and constituting one of said annular side walls,

said third rotor having a surface constituting the other of said side walls, a pump impeller disposed in said pump chamber, fiuid inlet and outlet means for said pump chamber, means for moving said second rotor to vary the volume of said pump chamber, means drivingly connecting s id first rotor to said third rotor for simultaneous rotation at the same speed.

6. A variable capacity pump comprising a stator having an annular pump chamber therein, said pump chamber having concentric cylindrical inner and outer walls together with annular side walls, first, second and third rotors journaled in said stator, said first rotor having a peripheral surface constituting said inner wall, said second rotor having a surface disposed between said inner and outer walls and constituting one of said annular side walls, said third rotor having a surface constituting the other of said side walls, a pump impeller disposed in said pump chamber, fluid inlet and outlet means for said pump chamber, means for moving said second rotor to vary the volume of said pump chamber, means drivingly connecting said first and second rotor for simultaneous rotation at the same speed.

7. A variable capacity pump comprising a stator having an annular pump chamber therein, said pump cham her having concentric cylindrical inner and outer walls together with annular side walls, first, second and third rotors journaled in said stator, said first rotor having a peripheral surface constituting said inner wall, said second rotor having a surface disposed between said inner and outer wall and constituting one of said annular side walls, said third rotor having a surface disposed between said inner and outerwalls and constituting one of said annular side walls, said third rotor having a surface constituting the other of said side walls, a pump impeller disposed in said pump chamber, fluid inlet and outlet means for said pump chamber, means for moving said second rotor to vary the volume of .said pump chamber, said last mentioned means including an actuator responsive to speed of said first rotor.

8. A variable capacity pump comprising a stator having an annular pump chamber therein, said pump chamber having concentric cylindrical inner and outer walls together with annular side walls, first, second and third rotors journaled in said stator, said first rotor having a peripheral surface constituting said inner wall, said second rotor having a surface disposed between said inner and outer walls and constituting one of said annular side walls, said third rotor having a surface constituting the other of said side walls, a pump impeller disposed in said pump chamber, fluid inlet and outlet means for said pump chamber, means for moving said second rotor to vary the volume of said pump chamber, said last mentioned means I including an actuator responsive to speed'of said first walls, said third rotor having "a surface constituting the i other ofsaid side walls, a" pump impeller disposed in said pump chamber, fluid inlet and outlet means for said pump chamber, means for moving said second rotor to vary the volume of said pump chamber, means drivingly connecting said first rotor to said third rotor for simultaneous rotation at the same speed, said third rotor having a central chamber, said first rotor having a portion extending into said central chamber said connecting means being disposed in said central chamber and being fastened to said'portion and to said third rotor.

10. A variable capacity pump comprising a stator having an annular pump chamber therein, said pump chamber having concentric cylindrical inner and outer walls together with annular side walls, first, second and third rotors journaled in said stator, said first rotor having a peripheral surface constituting said inner wall, said second rotor having a surface disposed between said inner and outer walls and constituting one of said annular side walls, said third rotor having a surface constituting the other of said side walls, a pump impeller disposed in said pump chamber, fluid inlet and outlet means for said pump chamber, means for moving said second rotor to vary the volume of said pump chamber, means drivingly connecting said first rotor to said third rotor for simultaneous rotation at the same speed, said third rotor having a central chamber, said first rotor having a por' tion extending into said central chamber said connecting means being disposed in said central chamber and being fastened to said portion and to said third rotor, said connecting means comprising a sleeve surrounding said portion, a pair of universal joint couplings secured to the ends of said sleeve, one coupling engaging said portion and the other coupling engaging said third rotor.

ll. A variable capacity pump comprising a stator having an annular pump chamber therein, said pump chamber having concentric cylindrical inner and outer walls together with annular side walls, first, second and third rotors journaled in said stator, said first rotor having a peripheral surface constituting said inner wall, said second rotor having a surface disposed between said inner and outer walls and constituting one of said annular side walls, said third rotor having a surface constituting the other of said side Walls, a pump impeller disposed in said pump chamber, fluid inlet and outlet means for said pump chamber, means for moving said second rotor to vary the volume of said pump chamber, a ring carried by said third rotor, said ring having a sealing engagement with the stufac'e of said second rotor, said third rotor havinga groove in said surface, said ring being movably seated in said groove, means resiliently urging said ring outwardly of said groove and into, sealing engagement with the surface of said groove and'into sealing engagement with the surface of said second rotor, said third rotor having recesses therein each communicating with the bottom of said groove, said'r'es'ilient means comprising a spring seated in each recess, means connecting said springs to said ring.

12. A variable capacity pump comprising a stator hav ing an annular pump chamber therein, said pump chamber having concentric cylindrical inner and outer walls together with annular side walls, first, second and third rotors journaled in said stator, said first rotor having a peripheral surface constituting said inner wall, said second rotorv having a surface disposed between said inner and outer walls and constituting 'on'e of said annular side walls, said third rot'or having a surface constituting the other of said side walls, a pump impeller disposed in said pump chamber, fluid inlet and outletsmeans for said pump chamber, means for movingsaid second rotor to vary the volume of said pump chamber, a ring carried by'said third rotor,- said rin'g'having a, sealing engagement with the surface of "said second rotor, said third rotor having a groove insaid surface, said rin'gbeing movablyseated in "said groove, means 'resili'ently urging said fingoutwardly of said groove "and into sealing engagement with. the surface of said second rotor, said third rotor having recesses therein each communicating with the bottom of said groove, said resilient means comprising a spring seated'in each recess, means connecting said springsto-said ring, said last mentioned means -in-'- eluding fingers on said-ring and each extending into said recesses.

13. A variable capacity pump comprising a stator having an annular pump chamber therein, said pump chamber having concentric cylindrical inner and outer walls together with annular side walls, first, second and third rotors iournaled in said stator, said first rotor having a peripheral surface constituting said inner wall, said second rotor having a surface disposed between said inner and outer walls and constituting one of said annular side walls, said third rotor having a surface -;constitnting the other of: said side walls, a pump impeller disposed in said pump chamber, fluid inlet and outlet means for said pump" chamber, means for moving said second rotor to varythe' volume of said pump chamber, means drivingly connecting said first and second rotor for simultaneous rota-- tion at the same speed, said'conne'cting means comprisinga radial notch in said second rotor and a radial and axial projection on said first rotor extending into said notch,

14. A variable capacity pump comprising a stator having an annular pump chamber therein, said pump chamber having concentric cylindrical inner and outer walls together with annular side walls, first, second and thirdrotors journaled in said stator, said first rotor having a peripheral surface constituting said inner wall, said second rotor having a surface disposed between said inner and outer walls and constituting one of said annular side walls, said third rotor having a surface constituting the other of said side walls, a pump impeller disposed in said pump chamber, fluid. inlet and outlet means for said pump chamber, means for moving said second rotor to vary the volume of said pump chamber, said inlet and outlet means including passages in said second rotor communicating with said pump chamber.

15. A variable capacity pump comprising a stator having an annular pump chamber therein, said pump chamber having concentric cylindrical inner and outer walls together with annular side walls, first, second and third rotors journaled in said stator, said first rotor having a peripheral surface constituting said inner wall, said second rotor having a surface disposed between said inner and outer walls and constituting one of said annular side walls, said third rotor having a surface constituting the other 'of said side walls, a pump impeller disposed in said pump chamb'cr, fi'uid inlet and outlet means for said pump chamber, means for moving said second rotor to vary the volume of said pump chamber, means for balancing the fluid pressure on opposite sides of said. first and second rotors.

16. A variable capacity pump comprising a stator having an annular pumpchamber therein, said pump chain ber having concentric cylindrical inner and outer walls together with annular side walls, first, second and third rotors journaled in said stator, said first rotor havinga peripheral surface constituting said inner wall, said second rotor having a surface disposed between said inner and outer'walls andcons'tituti'ng one of said annular sidewalls, said 'thir'd'rotor ihaving a sur face constituting the otherof said sidewalls, a pump impeller disposed in said :pump chamber, fiiiid'in leta 'nd outlet means for said pump chamber, means for moving said second rotor to vary the volumeof said pump chamber, said inlet and outlet means including passages in said second rotor communicating with said pump chamber, a pressure inlet chamber in said stator at one side of said secondrot'or, one of said pas sages communicating with said inle'tcham'ber.

17. A variable capacity .purnp comprising a statorha'ving an annular "pump chamber therein, said .pump chamber having concentric cylindrical inner and outer walls together with annular sidewalls, first, second and third rotors journaled in said stator, said first rotor having a peripheral surface constituting said inner wall, said second rotor having a surface disposed between said inner and outer walls and constituting one of said annular side walls, said third rotor having a surface constituting the other of said side walls, a pump impeller disposed in said pump chamber, fluid inlet and outlet means for said pump chamber, means for moving said second rotor to vary the volume of said pump chamber, said inlet and outlet means including passages in said second rotor communicating with said pump chamber, a pressure inlet chamber in said stator at one side of said second rotor, one of said passages communicating with said inlet chamber, a pressure exhaust chamber in said stator surrounding said second rotor, another of said passages extending to the periphery of said second rotor and communicating with said exhaust chamber.

18. A variable capacity pump comprising a stator having an annular pump chamber therein, said pump chamber having concentric cylindrical inner and outer Walls together with annular side walls, first, second and third rotors journaled in said stator, said first rotor having a peripheral surface constituting said inner wall, said second rotor having a surface disposed between said inner and outer walls and constituting one of said annular side walls, said third rotor having a surface constituting the other of said side walls, a pump impeller disposed in said pump chamber, fluid inlet and outlet means for said pump chamber, means for moving said second rotor to vary the volume of said pump chamber, said first and second rotors having axial stem portions rotatably journaled one in the other.

19. A variable capacity pump comprising a stator having an annular pump chamber therein, said pump chamber having concentric cylindrical inner and outer walls together with annular side walls, first, second and third rotors journaled in said stator, said first rotor having a peripheral surface constituting said inner walls, said second rotor having a surface disposed between said inner and outer walls and constituting one of said annular side walls, said third rotor having a surface constituting the other of said side walls, a pump impeller disposed in said pump chamber, fluid inlet and outlet means for said pump chamber, means for moving said second rotor to vary the volume of said pump chamber, said first and second rotors having axial stem portions rotatably journaled one in the other, said third rotor having a central chamber receiving said stem portions therein.

20. A variable capacity pump comprising a stator having an annular pump chamber therein, said pump chamber having concentric cylindrical inner and outer walls together with annular side walls, first, second and third rotors journaled in said stator, said first rotor having a peripheral surface constituting said inner Walls, said second rotor having a surface disposed between said inner and outer walls and constituting one of said annular side walls, said thind rotor having a surface constituting the other of said side walls, a pump impeller disposed in said pump chamber, fluid inlet and outlet means for said pump chamber, means for moving said second rotor to vary the volume of said pump chamber, said first and second rotors having axial stem portions rotatably journaled one in the other, said third rotor having a central chamber receiving said stem portions therein, a sleeve in said central chamber surrounding said stem portions, said sleeve having a connection with said third rotor and with the stem portion of said first rotor.

21. The combination of claim 1 wherein the peripheral surface of the first rotor has a block firmly attached thereto, said block constituting an impeller for said pumping chamber and having a rear overhanging portion slidably received in the drum of the second rotor whereby to allow horizontal movement of the second rotor but causing the first and second rotors to revolve as a unit about their common axis of rotation.

22. The combination of claim 21 wherein the second rotor has openings in its annular surface on each side of said impeller constituting inlet and exhaust ports, said third rotor having a surface comprising the other of said side walls.

23. The combination of claim 1 wherein the peripheral surface of said first rotor has an impeller extending therefrom and into said pumping chamber, said ring revolving about the axis of rotation of said third rotor and is slidably received therein, said ring having a cut away portion with the impeller located in the latter whereby said ring and impeller effect a pumping action.

References Cited in the file of this patent UNITED STATES PATENTS 1,276,372 Johnson Aug. 20, 1918 1,486,682 Phillips Mar. 11, 1924 1,990,750 Pigott Feb. 12, 1935 2,029,554 Berggren Feb. 4, 1936 2,146,037 Wahlmark Feb. 7, 1939 2,266,191 Granberg Dec. 16, 1941 2,426,361 Lester Aug. 26, 1947 2,453,271 Sales Nov. 9, 1948 2,484,789 Hill et al. Oct. 11, 1949 2,543,603 Schatzel Feb. 27, 1951 2,552,860 Oliver May 15, 1951 2,565,860 Lester Aug. 28, 1951 

